The present invention relates to sorting systems, and more particularly to conveyor sorting systems wherein articles are directed off the conveyor toward a desired location.
Systems and methods for sorting articles are generally known and practiced in many forms. A conventional manual sorting system includes a conveyor for transporting packages or articles to laborers or line workers, who physically remove or redirect the articles to a desired location according to a predetermined schedule or predetermined parameters, such as sorting by article description, size, etc. This type of system, however, is slow, labor intensive, and expensive.
More recently, automatic sorting systems have been developed that prove to be much faster and efficient than the manual system described above. Automatic sorting systems typically utilize a conveyor, such as powered rollers or a continuous belt, that directs articles along a path of travel. In order to redirect the articles, one conventional system provides means for lifting the articles off the conveyor and depositing the articles in a desired location. However, these systems are also slow and expensive. Another conventional automatic sorting system provides means for lifting a portion of the conveyor in order to slide the articles off one side of the conveyor to the desired location. These systems are also expensive and cumbersome due to the hydraulic or pneumatic lifting mechanisms utilized in these systems.
A more common conventional automatic sorting system includes means for pushing the articles off the conveyor to the desired location, such as a storage bin, tote, or other conveyor. A plurality of xe2x80x9cpushersxe2x80x9d act unidirectionally, meaning that the pushing action of each pusher is limited to one direction followed by a recoil or return action to the pusher""s initial position before the next pushing action can occur. These systems, however, are also limited in speed or xe2x80x9cthroughputxe2x80x9d because the articles must be spaced far enough apart to allow for the pusher to return to its initial position between each pushing action. This spacing requirement is true regardless of the number of pushers used in a particular system, as the articles must be spaced far enough apart so that subsequent articles are not hit by the returning pushers.
In order to decrease the spacing of the articles on the conveyor, which thereby increases throughput, automatic sorting systems have been developed having sorting devices that utilize a plurality of pushers extending from a rotating continuous belt positioned above the conveyor so that the pushers direct articles off the conveyor in a repeated fashion. Such a system is shown in French Patent 2620-054 to Ritoux (xe2x80x9cThe French Patentxe2x80x9d) and Japanese Patent 5-178451 to Sakagami (xe2x80x9cThe Japanese Patentxe2x80x9d). These systems, however, require multiple pushers in each sorting device in order to direct the articles off the conveyor, which adds complexity.
Another problem with these systems is that the systems are designed to push several articles off one particular side of the conveyor. In particular, the advantage stated by the French Patent states that the xe2x80x9cejectorsxe2x80x9d or paddles xe2x80x9cdo not need to return to their rest positions after operation,xe2x80x9d which according to the drawings of the French Patent means that the paddles travel a full revolution for each pushing operation. Indeed, the paddles of the French Patent and the Japanese Patent act as unidirectional pushers that push consecutive articles off only one side of the conveyor. Although the Japanese Patent shows opposing ramps for receiving articles directed from the conveyor, each ramp is provided for receiving a plurality of consecutive articles. In this regard, neither the French Patent nor the Japanese Patent teach or suggest sorting consecutive articles to opposite sides of the conveyor, as doing so would not utilize the multiple paddle feature of these patents. Even if the systems described in the French Patent and the Japanese Patent were operated to sort consecutive articles to opposite sides of the conveyor, these patents do not show any further sorting operations.
Another problem with conventional sorting systems that direct articles off either side of the conveyor is that the articles are sorted to distinct locations even if the sorted articles are the same. For example, articles sorted by a first sorter to one side of the conveyor are often directed to a first storage bin or tote, and articles sorted by a second sorter to the opposite side of the conveyor are directed to a second tote, even if the second sorter is immediately downstream of the first sorter. This creates production difficulties by requiring multiple totes for the same product or products meeting the same parameters.
Yet another problem with conventional sorters is that certain articles, such as thin, flat, or other irregularly shaped articles, are often missed by the pushers or sorters. In particular, these articles are so low that the pushers cannot sufficiently engage the articles to sweep them off the conveyor. Although it is possible to drag the pusher across the conveyor to sweep the articles off the conveyor, this is not desirable due to the resulting high friction built up as well as increased wear on the conveyor and pusher. Yet another problem with conventional sorters is that round or cylindrical articles are difficult or impossible to sort because of their tendency to roll off the conveyor.
Accordingly, there is a need to provide a sorting system that includes a simple sorting device for rapidly sorting articles. There is also a need to sort articles so that the number of totes for receiving the articles is minimized. Further, there is a need to differentiate and sort articles according to a particular requirement or condition so that the articles can be sorted into the desired locations. Further still, there is a need to provide a sorting system and a method for sorting articles wherein a wide variety of objects, including round, cylindrical, or flat articles can be easily sorted.
These and other needs are provided, according to the present invention, by a sorting system comprising a sorting device having a single, double-sided paddle for directing articles off either side of the conveyor. Advantageously, the spacing between the articles on the conveyor is substantially less than conventional systems, which thereby allows for greater throughput. Further, the articles sorted to either side of the conveyor are directed towards a common tote. Thus, substantially fewer totes are required for the sorting system of the present invention, which results in greater efficiency and utilization compared to conventional systems.
In particular, the present invention provides a sorting system comprising a conveyor, such as a continuous conveyor belt, that transports articles along a path of travel. The conveyor can be one of many conventional conveyors that are known in the art, and in one embodiment the conveyor includes an external surface having a plurality of raised portions, such as cleats, extending therefrom so that articles placed on the conveyor can be easily directed off the conveyor. At least one pair of opposing chutes are positioned along the conveyor that are sized for receiving the articles. Advantageously, the chutes are in communication with one another, so that articles directed into either chute are directed towards a common discharge end. In one embodiment, the common discharge end includes a discharge wall that is in selective communication with the chutes and can be pivoted or positioned from a discharge position to a storage position, as discussed below.
The sorting system of the present invention also includes a sorting device having a paddle for directing the articles from the conveyor to the chutes. More specifically, the paddle includes a first side and a second side that are operable to engage the articles so that the articles are directed from the conveyor to a respective chute. In one embodiment, the paddle includes a brush that can be in contact with the conveyor to ensure that particular articles, such as small, thin, or flat articles, are directed or swept off the conveyor into the chutes. The brush is particularly useful in combination with the cleated external surface of the conveyor, as the brush conforms to the surface of the conveyor and thereby ensures that these articles as well as cylindrical, round, and irregularly articles are directed from the conveyor. Advantageously, the paddle of the present invention can direct articles from either side of the conveyor without returning to an initial position between directing consecutive articles. In this manner, the sorting system of the present invention allows for substantially greater throughput than conventional systems.
The sorting device also includes a drive source for directing the paddle into engagement with the articles. In a presently preferred embodiment, the drive source is a pneumatic device that is operably connected to the paddle and which directs the paddle between a first position and a second position quickly and precisely. The drive source is operably connected to a detector, which detects the presence of an article at a particular point along the path of travel. The term xe2x80x9cdetectorxe2x80x9d is meant to be interpreted broadly, and preferably comprises a light-detecting device, such as a photocell, bar-code reader, or a color-code reader, that is known in the art.
As mentioned above, the pair of chutes according to the present invention are positioned across the conveyor from one another and are in communication with a common discharge end. More specifically, the chutes are preferably positioned opposite one another along the path of travel so that articles can be directed from the conveyor by the paddle. However, the chutes do not have to be directly opposite one another, as long as the chutes remain in communication with one another and have a common discharge end. According to a presently preferred embodiment, the common discharge end includes a pivotable discharge wall that is pivotable between a discharge position and a storage position. An actuator, such as a pneumatic or hydraulic piston, is preferably provided for moving the discharge wall between the discharge position and the storage position.
In one embodiment, a cover layer is attached to at least one of the chutes for assisting in directing the articles to the common discharge end. The cover layer is preferably formed of a low-friction, polymeric material and extends substantially the length of the chute. In this regard, the cover layer provides a relatively smooth path for the articles as they move towards the discharge end.
Associated methods are also part of the present invention. According to one method of the present invention, a method of sorting an article from a conveyor is provided comprising directing or transporting the article along a path of travel, detecting the article at a point along the path of travel, and directing the article from the conveyor to one of a pair of opposing chutes. As described above, the chutes are in communication with one another and have a common discharge end. Advantageously, the method provides a simple process for rapidly sorting items with fewer components, which increases line throughput.
Another method of sorting articles from a conveyor is provided comprising directing articles along a path of travel and directing a first article through a first chute to a tote by engaging the article with a first side of a paddle. In particular, the paddle moves from a first position to a second position in order to direct or sweep the article from the conveyor. The method also includes directing a second article along a second chute to a tote by engaging the article with the second side of the paddle, wherein the paddle moves from the second position to the first position. In one embodiment, the first article and the second article are directed into the same tote.
Accordingly, and as is explained in more detail below, the present invention provides a system and methods for sorting articles from a conveyor that overcomes the disadvantages of conventional sorting systems. The present invention is particularly advantageous for sorting small articles, such as nail polish bottles, combs, toothbrushes, and small electronics. The new system provides fast and efficient sorting by utilizing a single paddle or paddle to sort articles off either side of the conveyor, which allows for significantly increased throughput compared to conventional systems. Further, the new system directs articles from either chute to a common discharge end so that articles sorted from either side of the conveyor can be directed to the same tote, which significantly reduces complexity and improves efficiency.